This invention relates in general to dynamoelectric machines, and more particularly to a laminated rotor assembly and method for a dynamoelectric machine.
A dynamoelectric machine is a rotating electric machine capable of converting electric energy into mechanical energy (a motor) or converting mechanical energy into electric energy (a generator). A dynamoelectric machine includes a rotor housed within a stator. It is well known to form a rotor assembly by stacking many thin laminations of magnetic steel on a central shaft, axially compressing the stack and fixing the stack on the shaft. The laminations can be held together by bonding, welding, cleating or the like. Adhesives including an epoxy resin are commonly used to bond the laminations.
A specified orientation of each lamination is required to properly define the rotor poles and winding slots. Such orientation is commonly achieved by forming a key on the outer circumference of the shaft. A complementary keyway is formed on each lamination so that the laminations are properly aligned. In other prior art machines, splines are formed on the shaft and the laminations to align the stack on the shaft. Failure to properly align the laminations may cause rotor imbalance and difficulties in winding insertion. While laminations have been aligned in prior art devices, forming keys or splines in the outer circumference of the shaft is costly and is known to cause distortion in the shaft.
The art continues to seek improvements. It is desirable to economically secure rotor laminations to a shaft without causing distortion of the shaft. Furthermore, it is desirable to efficiently mount and align rotor laminations on a rotor shaft.